Spore Density Research Articles

Density and Phenotypic Diversity of Arbuscular Mycorrhizal Fungi in a Revegetated Tailing Storage Facility in Ghana

Arbuscular Mycorrhizal fungi (AMF) aid the establishment of vegetation on stressed soils as they contribute to soil ecological functions as well as improvement in plant growth. Understanding the mycorrhizal diversity and density within an area is an important step in harnessing the immense benefits of mycorrhiza. This study assessed the diversity and density of AMF in a revegetated tailing storage facility in Ghana. A balanced hierarchical sampling scheme with 4 stages and 72 sampling points was used over four sampling periods. Seventeen AMF spore types from nine genera (Acaulospora, Claroideoglomus, Diversispora, Gigaspora, Glomus, Racocetra, Rhizophagus, Septoglomus and Scutellospora) and five families (Acaulosporaceae, Claroideoglomeraceae, Diversisporaceae, Gigasporaceae and Glomeraceae) were isolated and identified from the samples. The density of spores varied between 24 and 817; 21 and 303; 21 and 321; and 24 and 875 spores 100 g-1 dry tailing solids respectively for the four sampled periods. The spore densities for the control samples also varied between 85 and 307; 65 and 248; 90 and 321 and 70 and 287 spores 100 g-1 dry soil for the respective sampling periods. Recorded spore densities varied significantly within sampling locations (p = 0.000) and between sampling periods (p = 0.000). The density and diversity of the AMF found in this study were relatively high and may have contributed significantly to the revegetation of the storage facility. These findings are important pointers for the adoption of mycorrhization in vegetation establishment and ultimately rehabilitation of decommissioned tailings storage facilities in Ghana. Further studies should however be done to determine how the various vegetation types found on the TSF affect AMF diversity and density.

Arbuscula Mycorrhizal Fungi on The Rhizosphere Three in The Ex-Sand Mine at Cipancur-Kuningan West Java

Sand and stone mining activities in Kuningan Regency cause damage to soil and environmental ecosystems, so reclamation and revegetation are carried out. The purpose of this study is to determine the existence of indigenous / local Arbuscular Mycorrhizal Fungi (FMA) found in the rhizozofer stands of Sengon (Paraserianthes falcataria) and Acacia (Acacia mangium) which are revegetation plants on the land of former sand and stone mines Cipancur village, Kalimanggis district, Kuningan regency. Sampling using the composite sampling method, FMA isolation technique using the wet pour method is then continued with the centrifugation technique and root colonization observation technique using the root staining technique (staining). The temperature of the ex-mining soil ranges from 28C – 29C, the soil pH is 5.5 including acidic, the soil moisture varies between wet, medium (slightly wet) and dry (dry) but during the rainy season the soil will become wet and even flooded. The results showed that there were 5 genera, it are Acaulospora, Glomus, Gigaspora, Sclerocytis and Scutellospora. The dominant genus is Glomus. The highest spore density was found in Sengon stands with 1,157 spores per 50 grams of soil. The highest percentage of AMF infection was at the root of Sengon stands at 69% from the ex-sand mining area.

Keanekaragaman Fungi Mikoriza Arbuskula pada Tegakan Kelicung (Diospyros macrophylla Blume) di KHDTK Rarung, Lombok Tengah

Kelicung tree (Diospyros macrophylla) is a native tree species of West Nusa Tenggara. It is a slow-growing tree with very good wood ornament, strength, and durability properties. Symbiotic mutualism between kelicung and mycorrhiza has not been documented. Mycrorrhiza is a mutualism symbiosis between fungi and plant roots that could improve plant growth due to increase nutrient and water absorbtion. Therefore, the objective of this study is to investigate mycorrhizal symbiosis in kelicung roots. Soil and root samples were taken in the Rarung Special Purpose Forest Area at 0 – 20 cm depth. Isolation and identification of arbuscular mycorrhizal fungi used screening and centrifugation methods to identify spore density, diversity, abundance, and frequency. Furthermore, root staining and colonization of arbuscular mycorrhizal fungi were carried out by observing the structure of vesicles, arbuscules, hyphae, and spores on Kelicung roots. The research results showed that the average number of spores found was 846 spores/50 g of soil. Spores were identified in two genera: Glomus sp and Acaulospora sp. Glomus spores found were round, the colour of the spores was yellow, the spores did not react when Melzer's solution was dropped, and the spore walls of the Arbuscular mycorrhizal fungi of the genus Glomus consisted of 1-2 layers of cell walls. Observation of root colonization, no structures of root arbuscular mycorrhizal fungi were found in Kelicung.
 Keywords: Acaulospora sp., Arbuscular mycorrhizal fungi, Diospyros macrophylla, Glomus sp., Kelicung

Soil Physicochemical Characteristics and Spore Density of Indigenous Arbuscular Mycorrhizal Fungi (AMF) in Different Vegetation Patches of a Marginal Upland in Central Philippines

To show the importance of plant-microbe association in stressed tropical landscapes, the study evaluated the physicochemical characteristics and indigenous arbuscular mycorrhizal fungi (AMF) spore density in selected vegetation patches of marginal upland soils in Central Philippines. Five quadrats were used in the study, namely Andropogon aciculatus (control plot), Imperata cylindrica, Chromolaena odorata, Melastoma malabathricum and mixed vegetation patch. Results showed that soils in the studied vegetation patches had different physicochemical characteristics and AMF spore density. Although all patches had clay soil texture and comparable water-holding capacity, mixed vegetation patch had moderate compaction (1.33 g cm-3) and higher porosity (50.31%) compared with the other patches, which had extreme compaction (1.37-1.65 g cm-3) and lower porosity (37.74-48.76%). In terms of chemical properties, soils in different patches had moderate (5.69) to strongly acidic pH (5.13), moderate organic matter (2.69-2.91%) levels, low P (2.67-3.94 ppm) content and above critical K levels (0.2-1.2 cmol+ kg-1). Results also revealed that C. odorata patch had the highest spore density count (11.33 spores 100 g-1), followed by mixed vegetation (9 spores 100 g-1), M. malabathricum (8.33 spores 100 g-1), and A. aciculatus patch having the lowest spore density count (4 spores 100 g-1). The significant spore density variability was attributed to the differences in soil’s physicochemical characteristics among the different vegetation patches and AMF host specificity. Spores detection, therefore, indicated AMF presence and helped the adaptation mechanism of the natural vegetation in this degraded upland.

Diversity of Arbuscular Mycorrhizal fungi under different agroforestry practices in the drylands of Southern Ethiopia

The conversion of an agroforestry based agricultural system to a monocropping farming system influences the distribution and composition of arbuscular mycorrhizal fungi (AMF). The aim of this paper was to analyze AMF species diversity, spore density, and root colonization across different agroforestry practices (AFP) in southern Ethiopia. Soil and root samples were collected from homegarden, cropland, woodlot, and trees on soil and water conservation-based AFP. AMF spores were extracted from the soil and species diversity was evaluated using morphological analysis and root colonization from root samples. The AMF spore density, root colonization and composition were significantly different among the AFP (P < 0.05). In this study, 43 AMF morphotypes belonging to eleven genera were found, dominated by Acaulospora (32.56%), followed by Claroideoglomus (18.60%). Home gardens had the highest spore density (7641.5 spore100 g− 1 dry soil) and the lowest was recorded in croplands (683.6 spore100 g− 1 dry soil). Woodlot had the highest root colonization (54.75%), followed by homegarden (48.25%). The highest isolation frequency (63.63%) was recorded for Acaulospora scrobiculata. The distribution of AMF species and diversity were significantly related to soil total nitrogen and organic carbon. The homegarden and woodlot AFP were suitable for soil AMF reserve and conservation.

Identification and molecular detection of Arbuscular Mycorrhizal Fungi colonized naturally in citrus roots in nurseries

Abstract. Sariasih Y, Subandiyah S, Widyaningsih S, Khurshid T, Mo J. 2023. Identification and molecular detection of Arbuscular Mycorrhizal Fungi colonized naturally in citrus roots in nurseries. Biodiversitas 24: 6283-6290. Citrus plants heavily depend on arbuscular mycorrhizal (AMF), a diverse collection of fungi. The objective of this study was to investigate the root colonization, spore density, spore morphology, and molecular identification of AMF colonizing four citrus root species: Japansche Citroen (Citrus limonia Osbeck.), Cleopatra mandarin (Citrus reshni), Salam (Fortunella japonica cv. "Salam"), and Rough Lemon (Citrus jambhiri). AMF was identified by observing spore morphology and molecular PCR methods using the group-specific primers of Glomeromycota, AML1/AML2. Based on the morphological observation, C. limonia was found with the highest root colonization (50%), followed by F. japonica cv Salam (44%), C. reshni (38%), and C. jambhiri (36%). The highest number of AMF spores was found on C. jambhiri rhizosphere soil, which had 1,379 spores/100 g of soil with the lowest percentage of root colonization. Three mycorrhizal genera were identified, with Funneliformis (syn. Glomus) being the most dominant genus, followed by Gigaspora and Acaulospora. The sequence of PCR products confirmed the highest similarity range from 83.7-99.0% to that of Funneliformis, followed by Acaulospora at a similarity range from 83.3-99.0% and found on all of the citrus species. The similarity sequence of the PCR products to that of Gigaspora ranged between 83.3-95.0%, which was only found on C. reshni and C. jambhiri.

Responses of arbuscular mycorrhizal fungal morphological traits and the diversity of spore-associated bacteria to simulated nitrogen deposition and drought in a Cunninghamia lanceolata plantation soil

Arbuscular mycorrhizal (AM) fungi play an important role in plant nutrient absorption and stress resistance. AM fungal spore-associated bacteria are essential for mycorrhizal colonization, but their responses to environmental changes remain largely unknown. We collected surface soil samples from a Chinese fir plantation in both summer and winter to investigate the responses of AM fungal morphological traits and spore-associated bacterial communities to simulated nitrogen deposition (40 kg N·hm-2·a-1 addition) and drought (-50% precipitation exclusion). Our results showed that nitrogen addition and precipitation exclusion significantly affected AM fungal spore density and extraradical hyphal length, respectively. AM fungal intraradical colonization rate, extraradical hyphal length and spore density were significantly differed between the two seasons. Compared to control (no nitrogen addition and no precipitation exclusion treatment), both nitrogen addition and precipitation exclusion significantly reduced spore density in winter, while precipitation exclusion alone and the combined nitrogen addition and precipitation exclusion significantly increased extraradical hyphal length in summer. The dominant spore-associated bacterial phyla were Proteobacteria, Acidobacteria, Actinobacteria, Chloroflexi, and Planctomycetes. Nitrogen addition and precipitation exclusion did not affect the diversity of spore-associated bacteria. However, the combined nitrogen addition and precipitation exclusion treatment altered the composition of the bacterial community, with significant variations between the two seasons. The spore-associated bacterial diversity was significantly higher and community variability (or turnover) was lower during summer than winter. Soil total nitrogen, nitrate nitrogen and dissolved organic carbon were important factors influencing the bacterial community composition. In all, the effects of nitrogen addition and precipitation exclusion on the morphological traits of AM fungi are seasonally dependent. The combination of nitrogen addition and precipitation exclusion has a significant impact on AM fungal spore-associated bacterial community structure.

The impact of inter- and intra-species spore density on germination of the food spoilage fungus Aspergillus niger

Aspergilli can be used to produce food but can spoil it as well. Both food production and spoilage are initiated by germination of the conidia of these fungi that have been introduced by inoculation and contamination, respectively. Germination of these spores includes activation, swelling, establishment of cell polarity, and formation of a germ tube. So far, only quantitative single-species germination studies of fungal spores have been performed. Here, spore germination of the food spoilage fungus Aspergillus niger was studied quantitatively in mono-culture or when mixed with other food-relevant aspergilli (Aspergillus nidulans, Aspergillus terreus, Aspergillus clavatus, and Aspergillus oryzae). In the presence of the germination inducing amino acids proline or alanine, but not in the case of the lowly inducing amino acid arginine, the incidence of swelling and germ tube formation was reduced when 35,000 extra conidia of Aspergillus niger were added to wells containing 5000 of these spores. Adding 35,000 spores of one of the other aspergilli also did not have an effect on germination in the presence of arginine, but the germination inhibition was stronger when compared to the extra A. niger spores in the case of alanine. A similar effect was obtained with proline. Together, results show that the germination of A. niger conidia is impacted by the density of its own spores and that of other aspergilli under favorable nutritional conditions. These results increase our understanding of food spoilage by fungi and can be used to optimize food production with fungi.

Making partners in the city: impact of urban soil P enrichment on the partnership between an invasive herb and arbuscular mycorrhizal fungi in a tropical city.

The mutualistic relationship between plants and arbuscular mycorrhizal (AM) fungi is essential for optimal plant nutrition, enabling plants to better withstand biotic and abiotic stressors and enhancing survival, reproduction, and colonization of new environments. Activities, such as soil enrichment or compaction, may decrease the benefits of AM fungi for plants, potentially reducing interactions in urban environments. Here, we examine this prediction by studying how urbanization alters AM interactions with the invasive herb Ruellia nudiflora (Acanthaceae). We collected soil and plants from deep urban sites (DUS; e.g., sidewalks), open urban sites (OUS; parks), and rural sites (RS) to analyse soil nutrient content, plant morphology, AM colonization rates, spore density, richness, and diversity. Contrary to predicted, DUS had the lowest soil nutrient concentration, except for phosphorus, reducing AM colonization. This supports the prediction of reduced AM interactions in urban environments. We also found that potassium affects the AM association. Urban plants had smaller and more compact root systems compared to their rural counterparts, but there were no discernible differences in AM fungi communities between urban and rural environments. Phosphorus enrichment in sidewalks is the main driver of reductionof R. nudiflora-AM fungi interactions in Mérida. More studies are needed to gain a better understanding of how AM fungi contribute to plant colonization in urban environments.

Assessing differential land use impacts on soil quality: A method based on log-response ratios and polygonal projections

Soil quality indices (SQI) used for assessing soil degradation are often developed using additive scoring functions. However, these SQI may lack reference values for interpreting their outputs and the capacity to differentiate changes in specific variables. To overcome these limitations, this study introduces SQI using Log Response Ratios (LRR) as measures of size effects caused by land use in physical, chemical, and microbiological soil quality indicators. LRR vectors projected 2D polygons with condensed change measures along their perimeters. This method was tested in andosols within the southeastern region of Antioquia, Colombia. These soils were subjected to contrasting stages of degradation determined by the extent of A-horizon removal due to land use practices. This study shows that mining and agriculture have detrimental effects on soil organic carbon and water contents, and that size effects vary significantly between land uses (p < 0.05). Microbiological features also exhibit distinct size effects, such as populations of culturable mesophilic bacteria and fungi, microbial basal respiration, spore density of arbuscular mycorrhizal fungi (AMF), their diversity, and total glomalin-related soil proteins (p < 0.05). The SQI proposed exhibited a negative correlation with SQI computed from scoring additive functions either considering the entire dataset (R2 = 0.87) or a minimum dataset (R2 = 0.90). This approach underscores the utility of using LRR geometrical analysis to assess global soil quality differences among land uses (p < 0.01), offering a visual, quantifiable representation of the effects of each land use over specific soil quality indicators.

Influence of arbuscular mycorrhizal fungi density on growth and metabolism of Handroanthus serratifolius (Vahl) S.O. Grose seedlings

AbstractStudies on the relationship between Handroanthus serratifolius and arbuscular mycorrhizal fungi (AMF) are limited in the literature. The influence of AMF spore density on plant development is fundamental information to determining the degree of benefits in this relationship. Therefore, the objective of this study was to investigate the effects of different AMF spore densities on thirty‐day‐old H. serratifolius seedlings, focusing on growth and biochemical parameters using a completely randomized experimental design with three different spore densities and control. The spore densities were classified as low, medium, and high, with 1.54, 3.08, and 12.35 spores g−1, respectively. Plant growth analysis, mycorrhizal colonization, nitrogen compound concentration, and carbohydrate analysis were performed. The medium spore density treatment showed the greatest increases in biomass, height, leaf area, and root volume. Furthermore, greater absorption of phosphorus and better dynamics in nitrogen metabolism were observed in mycorrhizal plants compared to the control since the ammonium and nitrate compounds were rapidly incorporated into protein and chlorophyll compounds. The carbohydrate analysis revealed the influence of source‐sink dynamics on sugar concentration in different plant parts. These findings support the importance of determining the appropriate spore density for assessing the symbiotic relationship between forest species and AMF.

Fern species and seasonal variation alter arbuscular mycorrhizal fungal colonization and co-occurrence patterns in the Heishiding Natural Reserve, South China

The establishment of arbuscular mycorrhizal fungi (AMF) symbiosis is generally considered an important pathway that assists ferns in their adaption to a variable environment in the forest ecosystem. However, how both fern species and seasonal variation affect the symbiotic characteristics and AMF community structure remains largely unknown. In this study, the AMF colonization status of 19 fern species in the Heishiding Nature Reserve located in south China was assessed. The effects of seasons on AMF colonization and community structure were also determined. The results showed that both seasons and species significantly affected AMF colonization rate (1.88–56.03 %) and spore density (94–546/25 g dry soil). In addition, according to principal component analysis, in spring, AMF colonization and spore density differed considerably from other seasons. The total AMF sequences detected in spring were significantly higher than in winter (p < 0.05). Glomus was the dominant genus, accounting for >75 % of all sequences. The AMF Chao1 and Faith PD indexes of Blechnum orientale Linn as well as the Shannon and Simpson indexes of Selaginella doederleinii Hieron were significantly higher in spring than in winter (p < 0.05). According to partial least squares path modeling, season had a significant influence on AMF colonization by varying the AMF alpha diversity rather than their community composition. Notably, network analysis showed that seasonal variation induced differences in AMF network structure, keystone taxa, and the number of links between species. This study highlights the symbiotic relationship between ferns and AMF in different seasons. The results provide novel insights on terrestrial ecosystem management and fern conservation from the perspective of plant-AM symbiosis.

Mycorrhizal fungal communities associated with three metal accumulator plants growing in an abandoned Pb smelting factory.

Plants associated with mycorrhizal fungi has the ability to establish on metal-contaminated soils playing an important role in phytoremediation programs. The objective of this study was to examine the presence of arbuscular mycorrhizal fungi (AMF) (spores density, diversity, indicator species, and root colonization) and dark septate endophytic fungi (DSE fungal root colonization) in three metal accumulator plants (Sorghum halepense, Bidens pilosa, and Tagetes minuta) growing in soils with high Pb content. The Pb content in AMF spores and plant biomass were also assessed. Rhizosphere soil samples were taken from the three dominant plant species at six study sites surrounding the abandoned Pb smelter and one uncontaminated site. The three studied plants were colonized by AMF and DSE fungi. A total of 24 AMF morphospecies were present in the Pb-contaminated areas. The AMF indicator species in the control site (non-contaminated area) was Funneliformis mosseae and in the most contaminated site were Gigaspora decipiens and Denticustata biornata. There was an increase in mycorrhizal variables such as the number of AMF vesicles, spore number, Pb content in AMF spores and plant biomass and DSE colonization (in Sorghum) with increasing soil Pb contamination, but a decrease in AMF diversity and richness was found. For upcoming soil restoration projects, it is crucial to understand the mycorrhizal fungi as well as the plant community that has adapted to the highly contaminated environment.

Biological Control of Three Fungal Diseases in Strawberry (Fragaria × ananassa) with Arbuscular Mycorrhizal Fungi

Similar to many other plant-based products, strawberries are susceptible to fungal diseases caused by various pathogen groups. In recent years, efforts have been made to combat these diseases using biological control methods, particularly the application of arbuscular mycorrhizal fungi (AMF). This study aimed to determine the effects of AMF (Funneliformis mosseae (Fm) and Gigaspora margarita (Gm)) on Rhizoctonia fragariae (Rf), Fusarium oxysporum (Fo), and Alternaria alternata (Aa), which are major pathogens for strawberry. The results showed that the effects of AMF on disease severity and plant growth varied depending on the pathogens involved. Rf caused the highest disease severity, followed by Fo and Aa, but all AMF treatments significantly reduced the disease severity compared to control treatments. The study also found that the specific AMF species and their combinations influenced plant growth responses under different pathogenic conditions. Different AMF treatments resulted in varying increases in plant fresh weight, dry weight, and length, depending on the pathogen. Moreover, the application of AMF led to increased levels of total phenolic content, antioxidant activity, and phosphorus content in pathogen-infected plants compared to control treatments. Fm was more efficient than Gm in increasing these biochemical parameters. The levels of root colonization by AMF were similar among different AMF treatments, but the effects on fungal spore density varied depending on the pathogen. Some AMF treatments increased fungal spore density, while others did not show significant differences. In conclusion, our research sheds light on the differential effects of AMF species on disease severity, plant growth, and biochemical parameters in strawberry plants facing diverse pathogens. These findings underscore the potential benefits of AMF in disease management, as they reduce disease severity and bolster plant growth and defense mechanisms.

Temporal dynamics of wild herbaceous arbuscular mycorrhizal fungi under crop succession: Rice-bean-amaranth-okra-eggplant

Arbuscular mycorrhizal fungi (AMF) are ubiquitous symbionts that colonize approximately 80% of wild and cultivated plants, with the exception of a few botanical families such as Amarantaceae, Brassicaceae, Cyperaceae, and Chenopodiaceae, which mycorrhizae less or not at all. These symbioses are important because they improve the hydro-mineral nutrition of plants. During a succession of crops on a plot, it is possible to observe the diversity of AMF in the soil; this work fits into this framework. The experiment was carried out in pots in a completely randomized block design with 5 crops, including rice-beans-amaranth-okra-eggplant, repeated 5 times. The temporal dynamics of AMF were assessed during crop succession on the same soil. The results show a high species richness for rice, with 23 AMF species compared to 9 AMF species found on amaranth. Spore density and root colonization frequency show the same trend, respectively 5 to 38 spores per 100 g soil for rice compared to 3 to 10 spores per 100 g soil for amaranth. The colonization frequency ranged from 79 to 80% in rice and bean, while amaranth was only colonized to 13%. The introduction of amaranth during crop succession contributes to a decrease in species richness, spore density and AMF colonization frequency, in contrast to other crops.

Evaluation of the Mycorrhizal Potential of Date Palm (Phoenix dactylifera L.) Rhizosphere Soils in the Figuig Oasis (Southeastern Morocco).

Date palm, an important crop in Morocco and many other arid regions around the world, faces significant challenges from wind, water shortages, and salinization, which contribute to vegetation loss and soil degradation in the harsh environmental conditions of oasis ecosystems with low soil fertility. Protecting and regenerating these degraded lands is crucial for sustainable agriculture and improving the dryland ecosystem. Arbuscular mycorrhizal fungi (AMF) comprise a vital element in this dynamic within the microflora of the soil rhizosphere. This study evaluated the potential in mycorrhizal soil and identified AMF in date palm rhizospheres in eight locations within the Figuig oasis (southeastern Morocco). This study found that Extension and Zenaga had more mycorrhizal propagules than other locations. Replanted maize (Zea mays L.) in these soils exhibited higher mycorrhization rates (91-93%) compared to that in other locations, with the Lamaiz site registering the lowest rate (39%). The phosphorus content was negatively correlated with the AMF spore frequency, intensity, and density, while a positive correlation was detected between the soil pH and the AMF spore frequency and density. The morphological identification of spores revealed Glomus as the predominant species, along with Acaulospora and Sclerocystis. This study represents an initial step toward the potential application of these fungi in environmental conservation and sustainable agriculture in arid regions.

Probiosimilarity Study: A Comprehensive Approach to Compare the Attributes of Marketed Probiotics Containing Bacillus clausii

&#x0D; &#x0D; &#x0D; Background: Probiotics are widely accepted functional foods for general well-being and a healthy lifestyle. A robust approach to evaluate the bio-similarities between marketed probiotics still needs to be developed. Aim: We aimed to define an approach that uses time-tested methods to evaluate pro-biosimilarity between different marketed probiotics. Methods: A total of five different Bacillus clausii formulations were compared with the international reference standard Enterogermina. The spore quantity and microbial purity of the samples were estimated. The antibiotic resistance strains in oral suspension samples were isolated and subjected to molecular characterization by 16S rRNA sequencing. The antibiotic susceptibility test was performed using commercially available antibiotics. The pH and transmittance of the samples were measured. Results: Bifilac Clausi had the highest, while Entromax had the lowest density of quality spores. None of the products had contaminant pathogenic microorganisms. Based on 16S rRNA sequencing, four strains from Bifilac Clausi and Enterogermina and one strain from other samples were identified. The identity of the strains from Bifilac Clausi matched those of Enterogermina. Bifilac Clausi and Enterogermina were resistant to the ten antibiotics tested. Conclusions: Among the different Indian brands of Bacillus clausii, only Bifilac Clausi was found to be a pro- biosimilar to the international reference standard, Enterogermina.&#x0D; &#x0D; &#x0D;

Bioassay test of Beauveria bassiana alginate pellet formulation on mortality of Spodoptera frugiperda in the laboratory

The attack level of Spodoptera frugiperda greatly influences the production of maize in the field. The use of insecticides for control certainly has many negative impacts so that they switch to more environmentally friendly controls. One of them uses the entomopathogenic fungus (EPF) Beuvaria bassiana which has the ability to aggressively paralyze insect larvae and imago that are affected by its spores. The B. bassiana can be mass produced in both solid and liquid media. The aim of this study was to test the effectiveness of the B. bassiana alginatepellet formulation on spore density and mortality of Spodoptera frugiperda test larvae in the laboratory. The efficacy test of the formulation on the test insects was carried out by dipping the test larvae feed into the B. bassiana alginate pellet suspension in each treatment using 50third instar of larvae. Corn had an effect on the spore density of B. bassiana alginate pellets, the highest spore density with conidia density of 2.35x108 conidia/mlwas found in the wheat flour treatment as well as with the highest percentage of mortality of Spodoptera frugiperda larvae, namely on day 6-9 DAA (days after application) in a row of 60%, 68% and 70%. In addition, it can be concluded that the alginate pellet formulation made from the active entomopathogenic fungus Beauveria bassiana is effective in controlling the population of Spoduptura frugiperda larvae.

Application of Trichoderma sp in pineapple biomass composting

Background: Pineapple litter has great potential as an organic source and if it can be decomposed properly it can turn into organic fertilizer. Pineapple biomass is difficult to decompose due to high lignin and cellulose content which slow down the decomposition process. Thus the addition of auxiliary microbes such as decomposer fungi is thought to increase the rate of decomposition. Aim: The aim of this research is determine the effect of Trichoderma sp. inoculum grown on rice substrate on pineapple litter composting Method: This study was in a completely randomized design (CRD) method consisting of 6 treatments with two stages of testing, there are fungal inoculum productivity test and application on pineapple litter. The spore density and viability (CFU) values were calculated for the inoculum that was incubated for 14 days to determine the productivity level of the inoculum. The pineapple litter given the inoculum is then subjected to a decomposition process for seven weeks. Pineapple litter compost was analyzed at the fourth and seventh week with the parameters observed were C-organic content and C/N ratio. Result: The results showed the spore density was 2.0 x107 spores / ml and the CFU value was 10.6x108 cfu / ml with 100% viability. The best compost had the lowest C-organic and C/N ratio value, there are P3 compost obtained 12,5% C-organic and P2 compost obtained 9,6 C/N ratio. Conclusion: The use of rice media as an inoculum medium for the Fungi Trichoderma sp. can increase the level of productivity of Fungi Trichoderma sp. with a viability percentage of 100% at 14 days of inoculum age.

Noticeable Shifts in Soil Physicochemical and Biological Properties after Contrasting Tillage Management in Crop Rotations of Bean, Maize, and Amaranth in Ecuadorian Highland Soils

Soil biological properties are sensitive indicators of soil quality changes due to perturbations occurred under agricultural management. The effects of contrasting tillage, increasing nitrogen fertilization doses, and crop rotations [e.g., bean, maize, bean (BMB) and bean, amaranth, bean (BAB)] on soil physicochemical and biological properties in an Andean soil from Ecuadorian highlands were evaluated in this study. Acid phosphatase, β-Glucosidase, fluorescein diacetate hydrolysis, microbial biomass carbon (Cmic), soil basal respiration (BR), arbuscular mycorrhizal fungi (AMF) spore density, total glomalin content (TGRSP), and soil physicochemical properties were analyzed. Conventional tillage (CT) and crop rotation showed significant effects on soil physicochemical and biological properties. Towards the final crop rotations, no-tillage (NT) promoted BR, TGRSP, and higher AMF spore density in both crop rotations; the Cmic kept stable along time in BMB and BAB, while BR doubled its value when compared to CT. Results indicated that the AMF spore density increased by 308% at the end of the BMB, and 461% at the end of the BAB, while TGRSP increased by 18% and 32% at the end of BMB and BAB, respectively. Biological traits demonstrated to be strongly associated to the organic matter accumulation originated from crop residues under the NT post-harvest which improved soil moisture, biological activity, and AMF interaction. The conservative soil management system has definitively improved general soil properties when compared to soil conditions under the intensive soil management system in this research.